hcl/hcl/hclsyntax/expression.go

1122 lines
28 KiB
Go

package hclsyntax
import (
"fmt"
"github.com/hashicorp/hcl2/hcl"
"github.com/zclconf/go-cty/cty"
"github.com/zclconf/go-cty/cty/convert"
"github.com/zclconf/go-cty/cty/function"
)
// Expression is the abstract type for nodes that behave as zcl expressions.
type Expression interface {
Node
// The hcl.Expression methods are duplicated here, rather than simply
// embedded, because both Node and hcl.Expression have a Range method
// and so they conflict.
Value(ctx *hcl.EvalContext) (cty.Value, hcl.Diagnostics)
Variables() []hcl.Traversal
StartRange() hcl.Range
}
// Assert that Expression implements hcl.Expression
var assertExprImplExpr hcl.Expression = Expression(nil)
// LiteralValueExpr is an expression that just always returns a given value.
type LiteralValueExpr struct {
Val cty.Value
SrcRange hcl.Range
}
func (e *LiteralValueExpr) walkChildNodes(w internalWalkFunc) {
// Literal values have no child nodes
}
func (e *LiteralValueExpr) Value(ctx *hcl.EvalContext) (cty.Value, hcl.Diagnostics) {
return e.Val, nil
}
func (e *LiteralValueExpr) Range() hcl.Range {
return e.SrcRange
}
func (e *LiteralValueExpr) StartRange() hcl.Range {
return e.SrcRange
}
// ScopeTraversalExpr is an Expression that retrieves a value from the scope
// using a traversal.
type ScopeTraversalExpr struct {
Traversal hcl.Traversal
SrcRange hcl.Range
}
func (e *ScopeTraversalExpr) walkChildNodes(w internalWalkFunc) {
// Scope traversals have no child nodes
}
func (e *ScopeTraversalExpr) Value(ctx *hcl.EvalContext) (cty.Value, hcl.Diagnostics) {
return e.Traversal.TraverseAbs(ctx)
}
func (e *ScopeTraversalExpr) Range() hcl.Range {
return e.SrcRange
}
func (e *ScopeTraversalExpr) StartRange() hcl.Range {
return e.SrcRange
}
// RelativeTraversalExpr is an Expression that retrieves a value from another
// value using a _relative_ traversal.
type RelativeTraversalExpr struct {
Source Expression
Traversal hcl.Traversal
SrcRange hcl.Range
}
func (e *RelativeTraversalExpr) walkChildNodes(w internalWalkFunc) {
// Scope traversals have no child nodes
}
func (e *RelativeTraversalExpr) Value(ctx *hcl.EvalContext) (cty.Value, hcl.Diagnostics) {
src, diags := e.Source.Value(ctx)
ret, travDiags := e.Traversal.TraverseRel(src)
diags = append(diags, travDiags...)
return ret, diags
}
func (e *RelativeTraversalExpr) Range() hcl.Range {
return e.SrcRange
}
func (e *RelativeTraversalExpr) StartRange() hcl.Range {
return e.SrcRange
}
// FunctionCallExpr is an Expression that calls a function from the EvalContext
// and returns its result.
type FunctionCallExpr struct {
Name string
Args []Expression
// If true, the final argument should be a tuple, list or set which will
// expand to be one argument per element.
ExpandFinal bool
NameRange hcl.Range
OpenParenRange hcl.Range
CloseParenRange hcl.Range
}
func (e *FunctionCallExpr) walkChildNodes(w internalWalkFunc) {
for i, arg := range e.Args {
e.Args[i] = w(arg).(Expression)
}
}
func (e *FunctionCallExpr) Value(ctx *hcl.EvalContext) (cty.Value, hcl.Diagnostics) {
var diags hcl.Diagnostics
var f function.Function
exists := false
hasNonNilMap := false
thisCtx := ctx
for thisCtx != nil {
if thisCtx.Functions == nil {
thisCtx = thisCtx.Parent()
continue
}
hasNonNilMap = true
f, exists = thisCtx.Functions[e.Name]
if exists {
break
}
thisCtx = thisCtx.Parent()
}
if !exists {
if !hasNonNilMap {
return cty.DynamicVal, hcl.Diagnostics{
{
Severity: hcl.DiagError,
Summary: "Function calls not allowed",
Detail: "Functions may not be called here.",
Subject: e.Range().Ptr(),
},
}
}
avail := make([]string, 0, len(ctx.Functions))
for name := range ctx.Functions {
avail = append(avail, name)
}
suggestion := nameSuggestion(e.Name, avail)
if suggestion != "" {
suggestion = fmt.Sprintf(" Did you mean %q?", suggestion)
}
return cty.DynamicVal, hcl.Diagnostics{
{
Severity: hcl.DiagError,
Summary: "Call to unknown function",
Detail: fmt.Sprintf("There is no function named %q.%s", e.Name, suggestion),
Subject: &e.NameRange,
Context: e.Range().Ptr(),
},
}
}
params := f.Params()
varParam := f.VarParam()
args := e.Args
if e.ExpandFinal {
if len(args) < 1 {
// should never happen if the parser is behaving
panic("ExpandFinal set on function call with no arguments")
}
expandExpr := args[len(args)-1]
expandVal, expandDiags := expandExpr.Value(ctx)
diags = append(diags, expandDiags...)
if expandDiags.HasErrors() {
return cty.DynamicVal, diags
}
switch {
case expandVal.Type().IsTupleType() || expandVal.Type().IsListType() || expandVal.Type().IsSetType():
if expandVal.IsNull() {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid expanding argument value",
Detail: "The expanding argument (indicated by ...) must not be null.",
Context: expandExpr.Range().Ptr(),
Subject: e.Range().Ptr(),
})
return cty.DynamicVal, diags
}
if !expandVal.IsKnown() {
return cty.DynamicVal, diags
}
newArgs := make([]Expression, 0, (len(args)-1)+expandVal.LengthInt())
newArgs = append(newArgs, args[:len(args)-1]...)
it := expandVal.ElementIterator()
for it.Next() {
_, val := it.Element()
newArgs = append(newArgs, &LiteralValueExpr{
Val: val,
SrcRange: expandExpr.Range(),
})
}
args = newArgs
default:
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid expanding argument value",
Detail: "The expanding argument (indicated by ...) must be of a tuple, list, or set type.",
Context: expandExpr.Range().Ptr(),
Subject: e.Range().Ptr(),
})
return cty.DynamicVal, diags
}
}
if len(args) < len(params) {
missing := params[len(args)]
qual := ""
if varParam != nil {
qual = " at least"
}
return cty.DynamicVal, hcl.Diagnostics{
{
Severity: hcl.DiagError,
Summary: "Not enough function arguments",
Detail: fmt.Sprintf(
"Function %q expects%s %d argument(s). Missing value for %q.",
e.Name, qual, len(params), missing.Name,
),
Subject: &e.CloseParenRange,
Context: e.Range().Ptr(),
},
}
}
if varParam == nil && len(args) > len(params) {
return cty.DynamicVal, hcl.Diagnostics{
{
Severity: hcl.DiagError,
Summary: "Too many function arguments",
Detail: fmt.Sprintf(
"Function %q expects only %d argument(s).",
e.Name, len(params),
),
Subject: args[len(params)].StartRange().Ptr(),
Context: e.Range().Ptr(),
},
}
}
argVals := make([]cty.Value, len(args))
for i, argExpr := range args {
var param *function.Parameter
if i < len(params) {
param = &params[i]
} else {
param = varParam
}
val, argDiags := argExpr.Value(ctx)
if len(argDiags) > 0 {
diags = append(diags, argDiags...)
}
// Try to convert our value to the parameter type
val, err := convert.Convert(val, param.Type)
if err != nil {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid function argument",
Detail: fmt.Sprintf(
"Invalid value for %q parameter: %s.",
param.Name, err,
),
Subject: argExpr.StartRange().Ptr(),
Context: e.Range().Ptr(),
})
}
argVals[i] = val
}
if diags.HasErrors() {
// Don't try to execute the function if we already have errors with
// the arguments, because the result will probably be a confusing
// error message.
return cty.DynamicVal, diags
}
resultVal, err := f.Call(argVals)
if err != nil {
switch terr := err.(type) {
case function.ArgError:
i := terr.Index
var param *function.Parameter
if i < len(params) {
param = &params[i]
} else {
param = varParam
}
argExpr := e.Args[i]
// TODO: we should also unpick a PathError here and show the
// path to the deep value where the error was detected.
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid function argument",
Detail: fmt.Sprintf(
"Invalid value for %q parameter: %s.",
param.Name, err,
),
Subject: argExpr.StartRange().Ptr(),
Context: e.Range().Ptr(),
})
default:
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Error in function call",
Detail: fmt.Sprintf(
"Call to function %q failed: %s.",
e.Name, err,
),
Subject: e.StartRange().Ptr(),
Context: e.Range().Ptr(),
})
}
return cty.DynamicVal, diags
}
return resultVal, diags
}
func (e *FunctionCallExpr) Range() hcl.Range {
return hcl.RangeBetween(e.NameRange, e.CloseParenRange)
}
func (e *FunctionCallExpr) StartRange() hcl.Range {
return hcl.RangeBetween(e.NameRange, e.OpenParenRange)
}
type ConditionalExpr struct {
Condition Expression
TrueResult Expression
FalseResult Expression
SrcRange hcl.Range
}
func (e *ConditionalExpr) walkChildNodes(w internalWalkFunc) {
e.Condition = w(e.Condition).(Expression)
e.TrueResult = w(e.TrueResult).(Expression)
e.FalseResult = w(e.FalseResult).(Expression)
}
func (e *ConditionalExpr) Value(ctx *hcl.EvalContext) (cty.Value, hcl.Diagnostics) {
trueResult, trueDiags := e.TrueResult.Value(ctx)
falseResult, falseDiags := e.FalseResult.Value(ctx)
var diags hcl.Diagnostics
// Try to find a type that both results can be converted to.
resultType, convs := convert.UnifyUnsafe([]cty.Type{trueResult.Type(), falseResult.Type()})
if resultType == cty.NilType {
return cty.DynamicVal, hcl.Diagnostics{
{
Severity: hcl.DiagError,
Summary: "Inconsistent conditional result types",
Detail: fmt.Sprintf(
// FIXME: Need a helper function for showing natural-language type diffs,
// since this will generate some useless messages in some cases, like
// "These expressions are object and object respectively" if the
// object types don't exactly match.
"The true and false result expressions must have consistent types. The given expressions are %s and %s, respectively.",
trueResult.Type(), falseResult.Type(),
),
Subject: hcl.RangeBetween(e.TrueResult.Range(), e.FalseResult.Range()).Ptr(),
Context: &e.SrcRange,
},
}
}
condResult, condDiags := e.Condition.Value(ctx)
diags = append(diags, condDiags...)
if condResult.IsNull() {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Null condition",
Detail: "The condition value is null. Conditions must either be true or false.",
Subject: e.Condition.Range().Ptr(),
Context: &e.SrcRange,
})
return cty.UnknownVal(resultType), diags
}
if !condResult.IsKnown() {
return cty.UnknownVal(resultType), diags
}
condResult, err := convert.Convert(condResult, cty.Bool)
if err != nil {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Incorrect condition type",
Detail: fmt.Sprintf("The condition expression must be of type bool."),
Subject: e.Condition.Range().Ptr(),
Context: &e.SrcRange,
})
return cty.UnknownVal(resultType), diags
}
if condResult.True() {
diags = append(diags, trueDiags...)
if convs[0] != nil {
var err error
trueResult, err = convs[0](trueResult)
if err != nil {
// Unsafe conversion failed with the concrete result value
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Inconsistent conditional result types",
Detail: fmt.Sprintf(
"The true result value has the wrong type: %s.",
err.Error(),
),
Subject: e.TrueResult.Range().Ptr(),
Context: &e.SrcRange,
})
trueResult = cty.UnknownVal(resultType)
}
}
return trueResult, diags
} else {
diags = append(diags, falseDiags...)
if convs[1] != nil {
var err error
falseResult, err = convs[1](falseResult)
if err != nil {
// Unsafe conversion failed with the concrete result value
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Inconsistent conditional result types",
Detail: fmt.Sprintf(
"The false result value has the wrong type: %s.",
err.Error(),
),
Subject: e.TrueResult.Range().Ptr(),
Context: &e.SrcRange,
})
falseResult = cty.UnknownVal(resultType)
}
}
return falseResult, diags
}
}
func (e *ConditionalExpr) Range() hcl.Range {
return e.SrcRange
}
func (e *ConditionalExpr) StartRange() hcl.Range {
return e.Condition.StartRange()
}
type IndexExpr struct {
Collection Expression
Key Expression
SrcRange hcl.Range
OpenRange hcl.Range
}
func (e *IndexExpr) walkChildNodes(w internalWalkFunc) {
e.Collection = w(e.Collection).(Expression)
e.Key = w(e.Key).(Expression)
}
func (e *IndexExpr) Value(ctx *hcl.EvalContext) (cty.Value, hcl.Diagnostics) {
var diags hcl.Diagnostics
coll, collDiags := e.Collection.Value(ctx)
key, keyDiags := e.Key.Value(ctx)
diags = append(diags, collDiags...)
diags = append(diags, keyDiags...)
return hcl.Index(coll, key, &e.SrcRange)
}
func (e *IndexExpr) Range() hcl.Range {
return e.SrcRange
}
func (e *IndexExpr) StartRange() hcl.Range {
return e.OpenRange
}
type TupleConsExpr struct {
Exprs []Expression
SrcRange hcl.Range
OpenRange hcl.Range
}
func (e *TupleConsExpr) walkChildNodes(w internalWalkFunc) {
for i, expr := range e.Exprs {
e.Exprs[i] = w(expr).(Expression)
}
}
func (e *TupleConsExpr) Value(ctx *hcl.EvalContext) (cty.Value, hcl.Diagnostics) {
var vals []cty.Value
var diags hcl.Diagnostics
vals = make([]cty.Value, len(e.Exprs))
for i, expr := range e.Exprs {
val, valDiags := expr.Value(ctx)
vals[i] = val
diags = append(diags, valDiags...)
}
return cty.TupleVal(vals), diags
}
func (e *TupleConsExpr) Range() hcl.Range {
return e.SrcRange
}
func (e *TupleConsExpr) StartRange() hcl.Range {
return e.OpenRange
}
type ObjectConsExpr struct {
Items []ObjectConsItem
SrcRange hcl.Range
OpenRange hcl.Range
}
type ObjectConsItem struct {
KeyExpr Expression
ValueExpr Expression
}
func (e *ObjectConsExpr) walkChildNodes(w internalWalkFunc) {
for i, item := range e.Items {
e.Items[i].KeyExpr = w(item.KeyExpr).(Expression)
e.Items[i].ValueExpr = w(item.ValueExpr).(Expression)
}
}
func (e *ObjectConsExpr) Value(ctx *hcl.EvalContext) (cty.Value, hcl.Diagnostics) {
var vals map[string]cty.Value
var diags hcl.Diagnostics
// This will get set to true if we fail to produce any of our keys,
// either because they are actually unknown or if the evaluation produces
// errors. In all of these case we must return DynamicPseudoType because
// we're unable to know the full set of keys our object has, and thus
// we can't produce a complete value of the intended type.
//
// We still evaluate all of the item keys and values to make sure that we
// get as complete as possible a set of diagnostics.
known := true
vals = make(map[string]cty.Value, len(e.Items))
for _, item := range e.Items {
key, keyDiags := item.KeyExpr.Value(ctx)
diags = append(diags, keyDiags...)
val, valDiags := item.ValueExpr.Value(ctx)
diags = append(diags, valDiags...)
if keyDiags.HasErrors() {
known = false
continue
}
if key.IsNull() {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Null value as key",
Detail: "Can't use a null value as a key.",
Subject: item.ValueExpr.Range().Ptr(),
})
known = false
continue
}
var err error
key, err = convert.Convert(key, cty.String)
if err != nil {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Incorrect key type",
Detail: fmt.Sprintf("Can't use this value as a key: %s.", err.Error()),
Subject: item.ValueExpr.Range().Ptr(),
})
known = false
continue
}
if !key.IsKnown() {
known = false
continue
}
keyStr := key.AsString()
vals[keyStr] = val
}
if !known {
return cty.DynamicVal, diags
}
return cty.ObjectVal(vals), diags
}
func (e *ObjectConsExpr) Range() hcl.Range {
return e.SrcRange
}
func (e *ObjectConsExpr) StartRange() hcl.Range {
return e.OpenRange
}
// ForExpr represents iteration constructs:
//
// tuple = [for i, v in list: upper(v) if i > 2]
// object = {for k, v in map: k => upper(v)}
// object_of_tuples = {for v in list: v.key: v...}
type ForExpr struct {
KeyVar string // empty if ignoring the key
ValVar string
CollExpr Expression
KeyExpr Expression // nil when producing a tuple
ValExpr Expression
CondExpr Expression // null if no "if" clause is present
Group bool // set if the ellipsis is used on the value in an object for
SrcRange hcl.Range
OpenRange hcl.Range
CloseRange hcl.Range
}
func (e *ForExpr) Value(ctx *hcl.EvalContext) (cty.Value, hcl.Diagnostics) {
var diags hcl.Diagnostics
collVal, collDiags := e.CollExpr.Value(ctx)
diags = append(diags, collDiags...)
if collVal.IsNull() {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Iteration over null value",
Detail: "A null value cannot be used as the collection in a 'for' expression.",
Subject: e.CollExpr.Range().Ptr(),
Context: &e.SrcRange,
})
return cty.DynamicVal, diags
}
if collVal.Type() == cty.DynamicPseudoType {
return cty.DynamicVal, diags
}
if !collVal.CanIterateElements() {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Iteration over non-iterable value",
Detail: fmt.Sprintf(
"A value of type %s cannot be used as the collection in a 'for' expression.",
collVal.Type().FriendlyName(),
),
Subject: e.CollExpr.Range().Ptr(),
Context: &e.SrcRange,
})
return cty.DynamicVal, diags
}
if !collVal.IsKnown() {
return cty.DynamicVal, diags
}
childCtx := ctx.NewChild()
childCtx.Variables = map[string]cty.Value{}
// Before we start we'll do an early check to see if any CondExpr we've
// been given is of the wrong type. This isn't 100% reliable (it may
// be DynamicVal until real values are given) but it should catch some
// straightforward cases and prevent a barrage of repeated errors.
if e.CondExpr != nil {
if e.KeyVar != "" {
childCtx.Variables[e.KeyVar] = cty.DynamicVal
}
childCtx.Variables[e.ValVar] = cty.DynamicVal
result, condDiags := e.CondExpr.Value(childCtx)
diags = append(diags, condDiags...)
if result.IsNull() {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Condition is null",
Detail: "The value of the 'if' clause must not be null.",
Subject: e.CondExpr.Range().Ptr(),
Context: &e.SrcRange,
})
return cty.DynamicVal, diags
}
_, err := convert.Convert(result, cty.Bool)
if err != nil {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid 'for' condition",
Detail: fmt.Sprintf("The 'if' clause value is invalid: %s.", err.Error()),
Subject: e.CondExpr.Range().Ptr(),
Context: &e.SrcRange,
})
return cty.DynamicVal, diags
}
if condDiags.HasErrors() {
return cty.DynamicVal, diags
}
}
if e.KeyExpr != nil {
// Producing an object
var vals map[string]cty.Value
var groupVals map[string][]cty.Value
if e.Group {
groupVals = map[string][]cty.Value{}
} else {
vals = map[string]cty.Value{}
}
it := collVal.ElementIterator()
known := true
for it.Next() {
k, v := it.Element()
if e.KeyVar != "" {
childCtx.Variables[e.KeyVar] = k
}
childCtx.Variables[e.ValVar] = v
if e.CondExpr != nil {
includeRaw, condDiags := e.CondExpr.Value(childCtx)
diags = append(diags, condDiags...)
if includeRaw.IsNull() {
if known {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Condition is null",
Detail: "The value of the 'if' clause must not be null.",
Subject: e.CondExpr.Range().Ptr(),
Context: &e.SrcRange,
})
}
known = false
continue
}
include, err := convert.Convert(includeRaw, cty.Bool)
if err != nil {
if known {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid 'for' condition",
Detail: fmt.Sprintf("The 'if' clause value is invalid: %s.", err.Error()),
Subject: e.CondExpr.Range().Ptr(),
Context: &e.SrcRange,
})
}
known = false
continue
}
if !include.IsKnown() {
known = false
continue
}
if include.False() {
// Skip this element
continue
}
}
keyRaw, keyDiags := e.KeyExpr.Value(childCtx)
diags = append(diags, keyDiags...)
if keyRaw.IsNull() {
if known {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid object key",
Detail: "Key expression in 'for' expression must not produce a null value.",
Subject: e.KeyExpr.Range().Ptr(),
Context: &e.SrcRange,
})
}
known = false
continue
}
if !keyRaw.IsKnown() {
known = false
continue
}
key, err := convert.Convert(keyRaw, cty.String)
if err != nil {
if known {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid object key",
Detail: fmt.Sprintf("The key expression produced an invalid result: %s.", err.Error()),
Subject: e.KeyExpr.Range().Ptr(),
Context: &e.SrcRange,
})
}
known = false
continue
}
val, valDiags := e.ValExpr.Value(childCtx)
diags = append(diags, valDiags...)
if e.Group {
k := key.AsString()
groupVals[k] = append(groupVals[k], val)
} else {
k := key.AsString()
if _, exists := vals[k]; exists {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Duplicate object key",
Detail: fmt.Sprintf(
"Two different items produced the key %q in this for expression. If duplicates are expected, use the ellipsis (...) after the value expression to enable grouping by key.",
k,
),
Subject: e.KeyExpr.Range().Ptr(),
Context: &e.SrcRange,
})
} else {
vals[key.AsString()] = val
}
}
}
if !known {
return cty.DynamicVal, diags
}
if e.Group {
vals = map[string]cty.Value{}
for k, gvs := range groupVals {
vals[k] = cty.TupleVal(gvs)
}
}
return cty.ObjectVal(vals), diags
} else {
// Producing a tuple
vals := []cty.Value{}
it := collVal.ElementIterator()
known := true
for it.Next() {
k, v := it.Element()
if e.KeyVar != "" {
childCtx.Variables[e.KeyVar] = k
}
childCtx.Variables[e.ValVar] = v
if e.CondExpr != nil {
includeRaw, condDiags := e.CondExpr.Value(childCtx)
diags = append(diags, condDiags...)
if includeRaw.IsNull() {
if known {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Condition is null",
Detail: "The value of the 'if' clause must not be null.",
Subject: e.CondExpr.Range().Ptr(),
Context: &e.SrcRange,
})
}
known = false
continue
}
if !includeRaw.IsKnown() {
// We will eventually return DynamicVal, but we'll continue
// iterating in case there are other diagnostics to gather
// for later elements.
known = false
continue
}
include, err := convert.Convert(includeRaw, cty.Bool)
if err != nil {
if known {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid 'for' condition",
Detail: fmt.Sprintf("The 'if' clause value is invalid: %s.", err.Error()),
Subject: e.CondExpr.Range().Ptr(),
Context: &e.SrcRange,
})
}
known = false
continue
}
if include.False() {
// Skip this element
continue
}
}
val, valDiags := e.ValExpr.Value(childCtx)
diags = append(diags, valDiags...)
vals = append(vals, val)
}
if !known {
return cty.DynamicVal, diags
}
return cty.TupleVal(vals), diags
}
}
func (e *ForExpr) walkChildNodes(w internalWalkFunc) {
e.CollExpr = w(e.CollExpr).(Expression)
scopeNames := map[string]struct{}{}
if e.KeyVar != "" {
scopeNames[e.KeyVar] = struct{}{}
}
if e.ValVar != "" {
scopeNames[e.ValVar] = struct{}{}
}
if e.KeyExpr != nil {
w(ChildScope{
LocalNames: scopeNames,
Expr: &e.KeyExpr,
})
}
w(ChildScope{
LocalNames: scopeNames,
Expr: &e.ValExpr,
})
if e.CondExpr != nil {
w(ChildScope{
LocalNames: scopeNames,
Expr: &e.CondExpr,
})
}
}
func (e *ForExpr) Range() hcl.Range {
return e.SrcRange
}
func (e *ForExpr) StartRange() hcl.Range {
return e.OpenRange
}
type SplatExpr struct {
Source Expression
Each Expression
Item *AnonSymbolExpr
SrcRange hcl.Range
MarkerRange hcl.Range
}
func (e *SplatExpr) Value(ctx *hcl.EvalContext) (cty.Value, hcl.Diagnostics) {
sourceVal, diags := e.Source.Value(ctx)
if diags.HasErrors() {
// We'll evaluate our "Each" expression here just to see if it
// produces any more diagnostics we can report. Since we're not
// assigning a value to our AnonSymbolExpr here it will return
// DynamicVal, which should short-circuit any use of it.
_, itemDiags := e.Item.Value(ctx)
diags = append(diags, itemDiags...)
return cty.DynamicVal, diags
}
if sourceVal.IsNull() {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Splat of null value",
Detail: "Splat expressions (with the * symbol) cannot be applied to null values.",
Subject: e.Source.Range().Ptr(),
Context: hcl.RangeBetween(e.Source.Range(), e.MarkerRange).Ptr(),
})
return cty.DynamicVal, diags
}
if !sourceVal.IsKnown() {
return cty.DynamicVal, diags
}
// A "special power" of splat expressions is that they can be applied
// both to tuples/lists and to other values, and in the latter case
// the value will be treated as an implicit single-value list. We'll
// deal with that here first.
if !(sourceVal.Type().IsTupleType() || sourceVal.Type().IsListType()) {
sourceVal = cty.ListVal([]cty.Value{sourceVal})
}
vals := make([]cty.Value, 0, sourceVal.LengthInt())
it := sourceVal.ElementIterator()
if ctx == nil {
// we need a context to use our AnonSymbolExpr, so we'll just
// make an empty one here to use as a placeholder.
ctx = ctx.NewChild()
}
isKnown := true
for it.Next() {
_, sourceItem := it.Element()
e.Item.setValue(ctx, sourceItem)
newItem, itemDiags := e.Each.Value(ctx)
diags = append(diags, itemDiags...)
if itemDiags.HasErrors() {
isKnown = false
}
vals = append(vals, newItem)
}
e.Item.clearValue(ctx) // clean up our temporary value
if !isKnown {
return cty.DynamicVal, diags
}
return cty.TupleVal(vals), diags
}
func (e *SplatExpr) walkChildNodes(w internalWalkFunc) {
e.Source = w(e.Source).(Expression)
e.Each = w(e.Each).(Expression)
}
func (e *SplatExpr) Range() hcl.Range {
return e.SrcRange
}
func (e *SplatExpr) StartRange() hcl.Range {
return e.MarkerRange
}
// AnonSymbolExpr is used as a placeholder for a value in an expression that
// can be applied dynamically to any value at runtime.
//
// This is a rather odd, synthetic expression. It is used as part of the
// representation of splat expressions as a placeholder for the current item
// being visited in the splat evaluation.
//
// AnonSymbolExpr cannot be evaluated in isolation. If its Value is called
// directly then cty.DynamicVal will be returned. Instead, it is evaluated
// in terms of another node (i.e. a splat expression) which temporarily
// assigns it a value.
type AnonSymbolExpr struct {
SrcRange hcl.Range
values map[*hcl.EvalContext]cty.Value
}
func (e *AnonSymbolExpr) Value(ctx *hcl.EvalContext) (cty.Value, hcl.Diagnostics) {
if ctx == nil {
return cty.DynamicVal, nil
}
val, exists := e.values[ctx]
if !exists {
return cty.DynamicVal, nil
}
return val, nil
}
// setValue sets a temporary local value for the expression when evaluated
// in the given context, which must be non-nil.
func (e *AnonSymbolExpr) setValue(ctx *hcl.EvalContext, val cty.Value) {
if e.values == nil {
e.values = make(map[*hcl.EvalContext]cty.Value)
}
if ctx == nil {
panic("can't setValue for a nil EvalContext")
}
e.values[ctx] = val
}
func (e *AnonSymbolExpr) clearValue(ctx *hcl.EvalContext) {
if e.values == nil {
return
}
if ctx == nil {
panic("can't clearValue for a nil EvalContext")
}
delete(e.values, ctx)
}
func (e *AnonSymbolExpr) walkChildNodes(w internalWalkFunc) {
// AnonSymbolExpr is a leaf node in the tree
}
func (e *AnonSymbolExpr) Range() hcl.Range {
return e.SrcRange
}
func (e *AnonSymbolExpr) StartRange() hcl.Range {
return e.SrcRange
}